From 10d34f74e2460013f11b158499f4675a475fc35e Mon Sep 17 00:00:00 2001
From: gongwei-130 <56567052+gongwei-130@users.noreply.github.com>
Date: Thu, 21 Aug 2025 14:06:50 -0700
Subject: [PATCH] fix: should return a invalid request response when schema
 missing (#9461)

---
 python/sglang/srt/entrypoints/openai/serving_chat.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/python/sglang/srt/entrypoints/openai/serving_chat.py b/python/sglang/srt/entrypoints/openai/serving_chat.py
index 042911f63..6179ab5c4 100644
--- a/python/sglang/srt/entrypoints/openai/serving_chat.py
+++ b/python/sglang/srt/entrypoints/openai/serving_chat.py
@@ -81,6 +81,11 @@ class OpenAIServingChat(OpenAIServingBase):
                 f"This model supports at most {server_context_length} completion tokens."
             )
 
+        if request.response_format and request.response_format.type == "json_schema":
+            schema = getattr(request.response_format.json_schema, "schema_", None)
+            if schema is None:
+                return "schema_ is required for json_schema response format request."
+
         return None
 
     def _convert_to_internal_request(